Yaws, which is triggered by a bacterial infection and can cause debilitating deformations, particularly in children under 15, once affected 50 million people worldwide before a massive treatment program in the 1950s almost succeeded in wiping it out.
When the disease's incidence went down by 95 percent, control programs were gradually dismantled.
"People assumed that the last few cases would be caught by public health systems, but yaws made a comeback," said Dr. Kingsley Asiedu, a WHO disease expert.
"This is an easily treatable disease that we are technically capable of eradicating," said Asiedu. For instance, since India began a nationwide effort to eliminate the disease in 1996, no cases have been detected in the subcontinent since 2003.
Yaws' resurgence stands as a cautionary tale for other disease eradication programs such as polio, which often falter in their final stages. "No one thought the last five percent of cases would be so difficult," said Asiedu.
At present, some 500,000 people, mostly in poor, rural areas, are affected by yaws, according to WHO.
The global health body said it had assembled experts from countries where yaws is endemic in Geneva this week to consider whether to revive the global program of 50 years ago in order to "eradicate this disease once and for all."
The nonfatal disease, which is spread by spiral bacteria similar to those that cause syphilis, can be treated with a single dose of cheap penicillin.